Stocking strategies for production of Litopenaeus vannamei (Boone) in amended freshwater in inland ponds

The performance of the Paci¢c white shrimp Litopenaeus vannamei (Boone) under various stocking strategies was evaluated in earthen ponds ¢lled with freshwater amended with major ions. Six 0.1-ha earthen ponds located in Pine Blu¡, AR, USA, were ¢lled with freshwater in 2003 and 2004, and potassium magnesium sulphate added to provide 50mgK L 1 and stock salt added to provide 0.5 g L 1 salinity. In 2003, three ponds either were stocked with PL15 shrimp (39 PLm ) for 125 days of grow out or with PL25 shrimp for 55 days (23 PLm ) followed by a 65-day (28 PLm ) growout period. In 2004, ponds were stocked with 7,13 or 30 PL15m 2 for 134 days of grow out. Salinity averaged 0.7 g L 1 during both years, and concentration of SO4 , K, Ca and Mg was higher, and Na and Cl was lower in amended pond water than in seawater at 0.7 g L 1 salinity. Potassium concentration inamendedwater was 52^61% of the target concentration. Shrimp yields ranged from 3449 kgha 1 in 2003 to 4966 kg ha 1 in 2004 in ponds stocked with 30^39 PL15m 2 for a125^134-day culture period. At harvest, mean individual weight ranged from 17.1 to 19.3 g shrimp . In ponds stocked with PL25 shrimp, yields averaged 988 and 2462 kgha 1 for the 1st and 2nd grow-out periods respectively. Gross shrimp yield in 2004 increased linearly from 1379^4966 kg ha 1 with increased stocking rate. These experiments demonstrated that L. vannamei can be grown successfully in freshwater supplemented with major ions to a ¢nal salinity of 0.7 g L .